What we have learned, from several thousand years of thinking about it, is that the only road to truth and understanding - in any sphere - is based upon doubt, questioning, discussion and experiment. This is the basis of what we now call the scientific method, but it should actually be called something much more general - like 'The Method of Reaching Fundamental Understanding of the Physical World, the Natural World and the Mind of Man'.

A consequence of the global nature of this method is that questions that are not susceptible to this approach are at one and the same time essentially unanswerable, fundamentally flawed and intrinsically meaningless. After all, if there is no universal bedrock of global truth upon which to base an answer, then the question is not conceptually valid. Thus, those who purport to have answers have only parochial belief to rely upon. As a result, a plethora of personal mystical philosophies stalk the world, propagated by purveyors who have a vested interest - in characterising doubt as dangerous, in misrepresenting science, and in misrepresenting results of science that undermine mystical philosophies.

The methods of science are manifestly effective, having made massive humanitarian contributions to society. It is this very effectiveness which the purveyors of mystical philosophies attack, because they recognise in it the chief threat to the belief-based source of their power and financial reward.

See Harold Kroto's website